You’ve slaved away on the treadmill and, not counting that one gelato incident, followed your diet to a “T.” But unless your scale is busted, no weight is coming off. So what are you supposed to do now? First of all, relax. You’re probably just making one of the many common mistakes that can sabotage the best-laid diet plan. Fortunately, these oversights are usually simple to fix with a little tweaking.

1. Underestimating calories – You think you’ve tallied up every calorie in your breakfast smoothie, lunch PB&J and that pasta you had for dinner — but did you count the mound of parmesan cheese on your spaghetti, and was that really just a 2-tablespoon serving of peanut butter on your sandwich? It’s incredibly easy to miscalculate daily calories, so watch portion sizes and keep a journal of every item that touches your plate, jotting all ingredients down separately. Or, follow WebMD’s advice and double your calorie estimate for large meals, which are the hardest to gauge accurately.

2. Skimping on food - When you eat too little, which is fewer than 1,200 calories a day for most women, your body scrambles to conserve energy and slows your metabolism. Your system is trying to help you through your self-induced famine because—shocker—your body cares more about survival than weight loss. Most women can shed pounds on 1,500 calories per day, or even more with regular exercise. Besides, 1,200 calories typically isn’t enough to get all of your essential vitamins and minerals. So stop starving yourself, already!

3. Losing sleep – If you’re missing your shuteye, your diet may not have a chance of success. In a study at Care Western University in Ohio, researchers found that sleep mattered even more than calorie intake when predicting weight gain. The study tracked 70,000 women for 16 years, and found that those who slept five or fewer hours per night were 30 percent more likely have gained 33 pounds than women who slept seven hours per night. Most surprising of all? The lighter sleepers actually ate less than their well-rested counterparts.

4. Skipping the weights – No, entering the weight room at the gym will not trigger the zombie apocalypse—or add manly bulk to your feminine frame, as women often fear. The truth is that females lack the hormones to grow man-sized guns, and building extra muscle mass actually speeds up your metabolism for easier weight loss. In fact, the Centers for Disease Control and Prevention claims that strength training can boost metabolism by up to 15 percent. Plus, the exercise builds stronger bones to ward off osteoporosis, and may help prevent heart disease.

5. Eating out – “Fat is flavor,” chefs love to say. That’s why that seemingly- safe salmon is drenched in butter, doubling the calories of a lean piece of fish. Most restaurant fare is rife with pitfalls; sauces, dressings and greasy cooking methods pile on calories and fat, making it virtually impossible to eat responsibly. If you must eat out, avoid anything fried or sautéed, and get all condiments on the side. Or, do your waistline a favor and cook at home.